Improvement in thresholds



ILPETES. PHOTo LITMOGRAPHER WASHINGTON D C N nitedtwte i amo @Biblica WILLIAM,` D. ST. CLAIR, OF CHICAGO, ILLINOIS.

lLetters Patent No. 100,461, dated March 1, 1870. A

IMPROVEMENT 1N T HRnsHoLDs.

'The Schedule referred to in these Letters Patent and making part: of the same I, WILLIAM D. ST. CLAIR, of Chicago, in the county of Cook, an'dState of Illinois, have invented a certain .lmpi'ovelneut in' the Threshold described in patent granted Joseph J ohnston April 6, 1869, No. 88,572,

` and consists in forming-the two strips of the threshold with `dovetail grooves, 'aud lnaking the frubber strip otcorrespondiug forni, the parts being so constructed' that the rubber lnay be drawn into vthe grooves and held without tacking.

z In the drawings which are hereto attached and made part of this specification `Figure 1 represents a door-sill or threshold to which my invention is applied.

Figure 2'is an end view ofthe same.

A is the strip of rubber or other` flexible material, provided forin the patent above referred to, connecting the wooden pieces B and C, and"consttutiug in4 combination with them a -door-sill.` The way in` which these parts have been` heretofore attached, is by means of screws, tacks, or brads driven through the lip (L and the edge of "the rubber strip A, 'and passing into the :nain part of the wooden piece B or C. This t method gives rise. to some objections; Thus the lip a, is liable to split, and the splinters soon wear out the rubber. And there is uo hold upon the edge ot' the rubber `between the tacks or screws, and the rubber is liable to work loose. And again there is a considerable expense of laborl and` material caused by this strip.

former method. By my invention and objections are obviated.

In carrying out -my invention, I malte these difiiculties Ll 1e groove E, which is cutin the edge of the stripsB und C, for

the purpose ot' receiving the edge ot' the 'rubber A, of a dovetailed 0r other l'orm, sothat it has a wider area within than atits opeuing at the surface of the. wooden The rubber strip is formed with a corresponding increase of thickness at its edge, sothat it cannot be inserted nor withdrawn through the narrow open- .iug ot the groove, but maybe slipped lengthwise in the groove.' Thus the parts may lbe expeditiously put together, and are securely held at all points without` `breakage or damage.

I do not claim attaching rubber to wood by means of a dovetail groove, but

What I do claim, as au improvement upon the `threshold described in the Letters `Patent referred to, is-

lhe described threshold, when the parts B C are formed with the dovetail grooves and the strip A with corresponding edges, the parts being so adapted to each other that the rubber may slide into the wood and be held without tacking, all as set forth.

WILLIAM D. ST. CLAIR. Vitnesses:

' T. O. CoNNoLLY, 1. W. ANGUs. 

